1. Field of the Invention
The present invention relates to lighters, and more particularly to disposable fuel cartridge lighters of the type in which liquid fuel stored under pressure in a fuel cartridge is vaporized in controlled fashion to provide the fuel in gaseous form to a flame ignited by a spark assembly.
2. History of the Prior Art
One common and well known lighter design vaporizes fuel such as butane stored in a pressurized liquid form so as to feed and thereby sustain a flame provided by a spark assembly. The vaporized fuel is fed to the flame in gaseous form through a burner valve having a switch which is manually actuated to hold the valve open and thereby sustain the flame. Upon release of the switch, the valve is closed to shut off the gas flow and terminate the flame.
Lighters of the type described employ various different arrangements of parts for vaporizing the pressurized liquid fuel and providing it to the burner valve in controlled fashion. Elongated elements such as hollow tubes and wicks are commonly provided within a container for the pressurized liquid butane so as to provide a vehicle for vaporization of the butane as it exits the container. Such elongated elements are often provided in combination with other elements which enhance the vaporization of the fuel and the formation of gas therefrom. Such other elements include metallic elements made of aluminum or similar materials which heat in response to the passage of the expanding liquid butane or other fuel to thereby enhance the vaporization of the fuel. Other elements which are used in such lighters comprise filters of various shapes and configurations which are designed to act as barriers to prevent fuel in liquid form from passing to and clogging the burner valve while at the same time readily passing fuel in vaporous or gaseous form to the burner valve.
Conventional arrangements for vaporizing and gassifying the pressurized liquid butane or other fuel in lighters suffer from a number of disadvantages. One such disadvantage relates to the size of such apparatus. For example, where elongated tubes or sticks are employed to provide vaporization in conjunction with liquid filtering action, the resulting arrangement often requires that the lighter be of some nominal or minimum size which may be larger than desired. It is quite difficult, for example, to make a lighter of relatively compact size such as one no larger in diameter than the common pencil. This es especially true where it is desired to maintain the fuel compartment of the lighter free of tubes, cotton, foam rubber and other such objects.
Disposable cartridge lighters of relatively compact size would be highly advantageous, particularly if they could be mass produced at relatively low cost. Such lighters could not rely on the use of expensive filters.
Examples of conventional lighter arrangements are provided by U.S. Pat. No. 3,523,006 of Piffath et al, U.S. Pat. No. 2,892,251 of Felt, U.S. Pat. No. 3,286,491 of Smith, U.S. Pat. No. 4,235,589 of Vallera, U.S. Pat. No. 4,177,646 of Guadagnin et al, U.S. Pat. No. 4,008,992 of Johnsson, U.S. Pat. No. 3,589,851 of Rabe, U.S. Pat. No. 3,827,852 of Chevallier, U.S. Pat. No. 3,327,504 of Smith, U.S. Pat. No. 2,836,044 of Zellweger and U.S. Pat. No. 3,597,140 of Rabe.
U.S. Pat. No. 3,523,006 of Piffath et al provides an example of a lighter which is of sufficiently complicated and costly construction as to prevent manufacture thereof in compact sizes and with sufficient economy to allow for disposal after only limited usage. Instead, the complex arrangement of Piffath et al is designed for prolonged use in conjunction with a dispensable fuel cartridge. An arrangement including a pair of rubber disks, a paper disk and a cloth disk acts as a pressure regulator for regulating the pressure of vaporized fuel. Cotton or foam rubber is placed in the fuel cartridge to enhance vaporization of the fuel. Gas entering an opening is forced to flow radially outwardly through a paper disk, around the outside of an imperforate disk and then radially inwardly through a cloth disk to an opening in another disk.
Various other ones of the above-noted patents utilize apparatus which includes different filter arrangements for passing fuel in vaporous or gaseous form to the exclusion of fuel in liquid form. Such arrangements tend to be of complex and in many cases expensive configuration, and often do not provide the degree of filtering action that is needed. U.S. Pat. No. 2,892,251 of Felt utilizes a pellet of compressed granular or powdered material. U.S. Pat. No. 3,286,491 of Smith utilizes a filter made of pressed and sintered granules of plastic or metallic oxide. The arrangement of U.S. Pat. No. 4,235,589 of Vallera uses a sintered metal element, as does U.S. Pat. No. 4,177,646 of Guadaguin. U.S. Pat. No. 4,008,992 of Johnsson utilizes a rubber plate. U.S. Pat. No. 3,327,504 of Smith utilizes a sintered material which may be sintered metal, sintered plastic, sintered ceramic or other materials. All of these materials and configurations increase production costs.
Accordingly it is an object of the invention to provide an improved compact and economical lighter, preferably one that can be made with sufficient economy so as to be disposable after limited usage.
It is a further and more specific object of the invention to provide a compact and economical arrangement for converting liquid fuel under pressure into vapors in a controlled manner and while at the same time filtering the liquid fuel.
It is a still further object of the invention to provide an improved fuel vaporizing element of compact configuration which provides for vaporization of the liquid fuel by heating in response to passage of the expanding fuel so as to enhance the vaporization of the fuel.
It is a still further object of the invention to provide a filter of improved and economical design for freely and readily passing vapors and gases of the fuel to the exclusion of liquid fuel and for reducing the pressure of the vapors and gases to control the flow of the gases to the burner valve.